Nano-sized additives found in many foods, cosmetics

What's lurking in your candy could be more frightening than just sugar and calories. A new breed of additives found in a range of foods is largely untested, and thepotential effects are unclear.

Some of the major research on the subject came about thanks to an eight-year-old and his candy.

Arizona State University engineering professorPaul Westerhoffnoticed that after eating a multi-coloured Gobstopper candy, hisson had a white coatingon histongue.

Curious about what caused it,Westerhoff studiedthe contents on the candyand found that it containedtitanium dioxide,an ingredientthat is added to all sorts of consumer products, including sunscreens, cosmeticsand food.

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Titanium dioxide found in foodsfrom candy to yogurt

The additive itself, which is used to make food appear whiter, is not necessarily harmful to humans. It's been approved by the U.S. Food and Drug Administration as"generally recognized as safe" for consumption for many years.

But manyfoods don'tjust containregular titanium dioxide they containanano-sizedversion of the additive.

That means the additive comes in the form of particles that arebillionths of a metre in size, instead of themicro-sizedchunksapproved for usein the1960s, which weremillionths of a metre in size.

Westerhoffand his colleagues tested dozens of foods andpersonal care products.

They found nano-sized titanium dioxidein about one-third of the items,includingMentos Fresh Mint Gum,Kool-Aid Blue Raspberry,Betty Crocker Whipped FrostingandM&Ms, as well as some types of Greekyogurt, cheeseand cereals.

Research still unclear on effects of nano-additives

The research, though, is unclear on how significant the difference between micro-sized and nano-sizedadditivesis.The micro-sized additives have been around for decadesand have been significantly tested.

The nano-sized version is the same molecule, but in smaller packets so it is unclear if it would have any difference in effect.

Jared Schoepf isa PhD student whostudies nano-scale additives such as titanium dioxide, working withWesterhoffatArizona State University.He said there are potential concerns with the nano-sized additives.

"Once it gets small enough so less than about 100 nanometres the particles areable to enter into your cells," he said. "And that's where some problems can arise. Once they get inside, they can create inflammationand other concerns that potentially can lead to, maybe, cancer or something further down the road."

There have been studies looking at the safety of the nano-additive. But at this point, the studies have beenrelatively small in scaleand have used huge doses of the products, well beyond normal consumption.

One study in particular reportedthat cultured intestinal cells exposed to large doses showed adverse effects such asDNA damageor damage to proteins and to the fats of the cell.

Nano-additives found in clothing as well as food

The studies suggest this is something to monitor with more realistic doses, butthat there isn't anyneed to panic just yet.

Generally, things on the nanoscalefunction verydifferently than onthe microscale. For example, when used as an additive at the nanoscale,silver hasantimicrobial propertiesand has been shown to be a persistent pollutant of our waterways. Nano-silveris often used inathletic gear to reduce smell in clothing.

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Titanium dioxide and other nano-additives are currently being investigated for what they do in the human gut. It has yet to be determined whether they are, in fact, absorbed into the cells, and if they are, whatthe consequences are forthe cell.